Measuring Conductivity Along Pine Tree Brook Reveals in an Increasing of Salinity Downstream
Frances Corcoran, Lara Metri, and Lilly Stoller
Introduction video
Introduction video.mp4
Figure 1: Map represents the areas along the Pine Tree Brook stream where data was collected. The stars highlight each discussed area along the stream.
Pine Tree Brook Map
Untitled: Apr 26, 2022 10:50 AM.webmMethods
Results
Figure 2: The Conductivity of 3 locations along Pine Tree Brook -Dam, Glover School and School Street in μS/cm.
Figure 3: The conductivity at School Street location on Pine Tree Brook from 3/02/22-4/14/22. Spike on 4/09/22 is due to the large snow storm in the greater Boston area.
Discussion
Stream samples farther downstream resulted in higher conductivity levels. The location the farthest upstream, the earthen dam, is the first area of the stream that encounters a road. The second location we collected data from was Glover, and this location had a significantly large jump in conductivity levels. The last location, and furthest downstream, was School Street which is relatively close to Glover and there was a smaller jump in conductivity levels. These increases in salinity are likely caused road salt that run into the stream when the snow melts or it rains. As the stream is exposed to more streets and other human impacts there is an increase in conductivity. Shown in figure 2 is the data collected using a conductivity sensor placed at the School Street location for over a month. The spikes represent the snow storms we had throughout early march where large amounts of road salt were being sprayed. The conductivity spikes in the stream following snow storms is likely a result of the distribution of road salt that accompanies storms. The road salt, a type of pollutant, enters the stream as surface runoff.
One important controlled variable we had was collecting the water samples on the same day to avoid any changes to the stream caused by the weather changes from day to day.
A possible next step, and something that would've been beneficial to our data, would be to have placed three long term conductivity sensors in all three locations over the same time period. It would have been interesting to compare the three sets of data and see how the same weather and conditions affect the different locations of the stream. Additionally, if we collected data at a few different locations we would have had more data to compare the varying conductivity levels to. Specifically, it would have been beneficial to collect data from a location in between the earthen dam and Glover School because they are relatively far away from each other. It also would have been interesting to collect samples from Headwaters and seen how the conductivity levels differ from Headwaters to the earthen dam as there is no roads or direct human impact in between them. Data collected from headwaters would act as a controlled group, and would help indicate the natural conductivity levels in the stream.